Fourier sine and cosine series of these functions?

Question

What are the Fourier sine and cosine series of these functions: for $0 < x < \pi$:

1. $x$

2. $x(\pi − x)$

3. $e^{-\alpha x}$

4. a function which is 1 when $0 < x < \frac{\pi}{2} $, -1 when $\frac{\pi}{2} < x < \pi $